Feeding the world’s growing population is a complex challenge, one made no easier by the amount of food we waste. Approximately 222 million tons of food go uneaten in industrialized countries every year, according to the UN’s Food and Agriculture Organization. That’s almost as much food as sub-Saharan Africa produces.

But it doesn’t stop there. In Europe alone, food waste weighs in at 89 million tons, and that number could rise in the next few years unless we take significant action.

And, according to the newly formed ReFED organization, whose acronym stems from “rethinking food waste through economics and data”, the United States spends $218 billion a year “growing, processing, transporting and disposing of food that is never eaten”.

Food waste in Europe by sector (2012)

Image: FUSIONS EU report

So, keeping in mind the Sustainable Development Goal to “halve per capita global food waste at the retail and consumer levels and reduce food losses along production and supply chains”, what can be done?

ReFED has developed a roadmap to reducing waste that includes 27 approaches, each of which fits into the following categories defined by the EPA’s Food Recovery Hierarchy: recovery, recycling and prevention.

Recovery refers to food redistribution; recycling, to re-use for energy and agriculture. But 12 other proposed ideas focus on preventing waste from even occurring. Like Benjamin Franklin once said: “An ounce of prevention is worth a pound of cure.”

Of all the prevention-focused ideas, it’s consumer education that will have the greatest impact, according to ReFED’s economic analysis. This result dovetails with EU studies that show the majority of food waste occurs in individual households.

However, other prevention approaches taken together would make an even greater impact. These ideas include changes such as employing standardized data labeling, dynamic expiration dates, spoilage-prevention packing, value-added processing and better inventory management.

All of these approaches may benefit from an unlikely source: chemistry.

When good food goes bad

The terms “chemical” and “fresh food” aren’t generally associated with each other, but indeed the field of chemistry – or, more specifically, chemical sensing – can now provide another path to preventing food waste.

As fruit and meat change over time, so too does their chemical signature. Sensing and quantifying these signatures provides information that companies and individuals can use for proper storage, and timely transportation and consumption.

In the case of fruit, the operative chemical is ethylene. Ethylene is a universal plant hormone that signals the ripeness of many types of fruit such as bananas, apples, tomatoes, avocados or mangos. Sensing ethylene can provide invaluable information on the state of fruit ripeness.

Much is already known about a particular fruit’s ethylene emission and absorption. This has given rise to common kitchen truths, such as not storing bananas in the same basket as other fruit: bananas give off high concentrations of ethylene, causing adjacent fruit to ripen faster.

In the case of meat, fish and other food products, the chemical signature of biogenic amines, as well as sulfides and other gases, provides information on food safety and quality.

Biogenic amines are markers of microbial metabolism. Some of these compounds have names, such as putrescine and cadaverine, that clearly indicate that ingesting high levels could lead to serious cases of food poisoning. Additionally, aggressive cooking at high temperature does not necessarily reduce the level of biogenic amines.

Senses for the digital world

One US-based company is currently proving the concept of using chemical sensors in the food industry. C2Sense uses a proprietary technology based on advanced nanotechnology techniques to produce sensors that can detect certain gases, including ethylene and biogenic amines.

The sensors deliver real-world chemical information about food freshness, toxic gases, feedstock chemicals and air quality – and can be seamlessly integrated into electronic networks, providing “a sense of smell for the digital world”.

Change begins at home

Numerous studies on food waste state that data collection on the subject is imprecise, but one fact is entirely consistent: most waste happens in individual households. Though better food storage, packing and transportation are all important, real impact will only be achieved by changing our habits at home.

Chemical sensors also hold promise here – as an artificial nose, alerting us when food is ripe or past its prime, or even dangerous to consume.

So in summary, chemical sensors could help us a lot, whether it’s keeping us away from spoiled food or reducing food waste in line with the UN’s Sustainable Development targets.